Underreamer



E. C. AND W. W. WILSON.

. UNDEIIIIEAMER.

APPLICATION FILED 050.20, IsI.

1 ,344,327. Patented June 22, 1920.

THEIR ATTURN underreamer constructions.

UNITED STATES PATENT OFFICE.

ELIHU C. WILSON AND WILLIAM W. WILSON, OF LOS ANGELES, CALIFORNIA,-ASSIGNORS T0 SAID WILLIAM W. WILSON.

UNDERREAMER.

Specification of Letters Patent;

Patented June 22, 1920.

Application iled December 20, 1916. Serial No. 138,055.

such as are used for enlarging well holes to permit the lowering ofcasing therein as the development of the hole proceeds. It is aparticular object of the present invention to provide an improvedunderreamer in which the cutters or expansible and collapsible cuttersor members which are usually present in such a device may be capable ofa relatively greater range of lateral expan-` sion in accompaniment witha given distance of play lengthwise of the underreamer body. The presentunderreamer constitutes an improvement upon or modification with respectto an underreamer such as that disclosed by us in a prior applicationfor U. S.

Letters Patent, filed by us Sept. 27, 1916,

Sei- No. 122,481, but it is to be understood that the broad laspects andfeatures of the present invention are not confined in use landadaptation and application to any one particular type and organizationof underreamer, but that the same may be embodied in and applied to awide range of varying 'lhe invention has for further objects theprovision of an improved underreamer which will be generally superior inpoint of relative simplicity and inexpensiveness of construction andorganization, taken in connection with durability, freedom fromliability to disorder and derangement of parts and features, facility inassemblage and dismantling or disconnecting of parts and features,positiveness and efficiency in operation, and general serviceability. Afurther particular object of the invention consists in the formaprior tolowering the underreamer to the zone of performance. Certain features ofcutter formation incident to their coperatlon with the other features ofthe construction likewise enter into the present invention.

lVith the above and other objects in View, the invention consists in thenovel and useful provision, formation, construction, combination,association and inter-relation of parts, members and features, all ashereinafter described, shown in the drawing and finally pointed out inclaims.

In the drawing:

Figure 1 is a longitudinal sectional view,

l partly broken away, and partly in elevation,

of an improved underreamer constructed and organized to embody theinvention; one of the cutters or bits being omitted for clearness ofillustration;

Fig. 2 is a view similar to Fig. 1 showing the cutters in contracted orcollapsed positions, such cutter being shown in expanded workingposition in Fig. 1; the cutters being shown held temporarily collapsedfor introduction within the casing in Fig. 2, in accordance with thepresent invention;

Fig. 3 is an elevation of the spring-actuated cutter-carrying rod shownin Figs. 1 and 2, the same being in detached position. and being a viewat right angles to the plane of vision in Figs. 1 and 2;

Fig. L1 is a side elevation of one of the cutters shown in Figs. 1 and 2in -detached posi-k tion, looking toward the inner face of the shankthereof;

Fig. 5 is a detail transverse sectional view taken upon the line905-505, Fig. 1, and looking upwardly;

Fig. 6 is a bottom end or plan view of the body of the underreamer withthe cutters land spring-actuated cutter-carrying rod removed; and

Fig. 7 is a detail inner face view of one of the underreamer cuttersshown likewise in detached position.

Corresponding parts in all the figures are designated by the samereference characters.

Referring with particularity to the drawing, the underreamer showntherein as embodying the invention com rises an elongated body Aprovidedi with an internal longitudinal bore or chamber 7 and having atits upper end one member 8* of a taperjoint, such member being knowninthe art as a taper threaded pin. By this ]o1nt member the underreamer isconnected with the sinker bar, jars, or other features of a str ing oftools utilized in the reaming o eratlon, and which string is suspendedat t e lower end of the cable by which the underreamer and string arevertically reciprocated in the hole in the reamin operation, pursuant towhich the cutters l disposed' at the lower `end of the reamer body arecaused to attack the shoulder or annular formation beneath the casing.to chip, cut or break same away so that the further lowering of thecasing may be permitted. The lower end of the reamer body A is shown asformed into o1' provided with a chamber 8 or bowl mouth, the walls ofwhich are slightly upwardly and inwardly inclined, and at the extremelower orifice of which are provided two downwardly ranging opposedeXtensions or lugs 9 constituting inthrust bearings for the cutters andalso provided with upper spreading bearings 9a and lower spreadingbearings 9b which coperate with the cutters in both the expanding andcollapsing actions thereof. Within the longitudinal bore or chamber 7 inthe body A, is disposed a spring-actuated rod 10 which is surrounded bya coil compression spring 11 which bears at its upper end upon anadjusting nut 12 threaded to the upper end of such rod 10; and the lowerend of such spring 11 bears upon or is seated upon means Z) forassembling together the body A, the rod 10 and its spring 1l, and thecutters B, such means likewise serving as a stop or seat for thelowerend of the spring 11.

At the lower end of the rod 10 are provided separate means c and d ofoperative connection for the respective cutters B with suchspring-actuated rod 10.' Likewise, the lower end of the body Apreferably adja-y cent to the upper region of the bowl mouth or chamber8 is provided with a lateral opening or hole 13 accommodating means efor temporarily and positively retaining the spring-actuated rod indepressed position and consequently retaining the cutters B incontracted or collapsed positions, namely, the positions shown in Fig.2.

Inasmuch as the general formation of the reamer body A and of thespring-actuated rod and its spring, and 4of the means b for assemblingtogether the parts and stopping the lower end of the spring, are eitherwell known in the art or described and disclosed and claimed in saidprior application by us filed, or in other applications for LettersPatent previously filed by us, and inasmuch as the present inventionparticularly pertains to the formation and relative arrangement and modeof operation and principle of action of the lower end of thespringactuatedv rod 10 and the means c and d thereon, together with thecutters 'B, and the means e for temporarily retaining the cutters incontracted positions, only brief reference will be made to such wellknown and heretofore produced features, emphasis and particulardescription and statement being concentrated upon the featuresparticularly characterizing the` present invention.

As shown, the means b comprise a key 14 which may be passed endwisethrough a transverse slot 15 in the reamer body A and through a furthertransverse elongated slot 16 in the spring-actuated rod 10 beneath thespring 11, and held in position by a lng or head 16a at one end of thekey which is received within a recess 17 in the reamer body, and, by acotter pin 18 which is passed through an opening 19 in the other end ofthe key 14 and engages with the body A exteriorly of the same.

The lower end of the spring-actuated rod 10 is enlarged as shown, in theportion in which the slot 16 is formed, to strengthen the same, and theextreme lower portion thereof, 10, is flattened at its opposed sides toreceive in engagement the inner faces of Athe Shanks of the cutters,such. portion being likewise laterally expanded or broadened. Thisbroadening provides for reception of the means c and d, each of which isshown as a separate pivot pin positively seated in such portion 10l andpreferably introduced Within a recess therein within which it is firmlywelded. These pins, shown as cylindrical, are when seated in theirrespective openings in or through the portion 10, disposed to projectoppositely from such portion 10, and out of registration or coincidence.Eachpin is preferably thus disposed at a separate side of thelongitudinal axis of the rod 10, and their axes are parallel. To each ofsuch pins is applied a separate one of the cutters B, each such cutterhavi a shank ortion 2() having an inner flat ace 20* an provided with atransversely or laterally elongated or enlarged socket 20b whichreceives the respective pin cor d, to pivotally center the respectivecutter upon and pivotally suspend it from the respective pin andrepsultantly from the rod 10, and eccentrically with respect to thelongitudinal axis of such rod. Each cutter is mounted upon the pin c orl which is disposed at the side of the longitudinal axis of the rod 10at which the cutter in the main operates', thus generally disposing thecutter in its working zone in the main at one side of the of thespring-actuated rod. eretofore in lon ritudinal axis ing body portion 20at the lower extremityl cutter-carrying rod, is onedistinguishingfeature of the present invention. Each cutter B isprovided with a laterally rangof which is provided the working orcutting edge 20, such body being provided at its upper end with a ridingshoulder 20e for engagement with the lower extremity 8a ot the bowlmouth 8 for coperation to transmit the upthrust of the cutter to thebody of the reamer; and likewise for engagement with the lower end ofthe shoe or casing 21 in Fig. 1, to produce collapsion of the cuttersupon the beginning of the elevation-of the reamer, which is accomplishedby temporary relative movement of the cutters and their rod 10, and thebody A. The upper portion of each body 20c is planed off as at 20, ateach-side to produce a downwardly and inwardly inclinedv shoulder QOfgwhich coperates with the respective lower spreadingv bearing -9b uponthe respective lug 9; and the cutter body is provided beneath vsuchshoulders 20g with lateral shoulders 20h, the inner faces of which -formbearings coperating with the upper spreading bearings 9*.

The upper spreading bearings 9 are sharply upwardly and outwardlyinclined; and the lower spreading bearings 9b partake of a less acuteupward inclination.

The means e is shown in the particular form illustrated in the drawingas including a stop pin which is of proper dimension to be freely passedinto the opening 13 so that its inner end may be brought within thechamberl 8 and likewise ,within the elongated slot 16 in the sprin-actuated rod 10 when the rod is in lowere position and the cutters arecollapsed or contracted. Thus the action of the spring 11 is resistedand the cutters maintained in collapsed or'contracted positions forentering in the casing, until such pin is withdrawn and thespringactuated rod is freed. It is manifest that the slot 16 is onlyutilized to receive this stop pin for motives of convenience and toobviate the necessity of'providing any other receptive. opening for suchpin, although such other opening or other complementary formation uponthe rod may be provided as desired. jThe shanks 20 of the cutters areformed to complement the upwardly and inwardly inclined inner walls ofthe bowl mouth 8, to such an extent as to 'produce a proper working fit,and at the same time to permit of pivotal action of the cutters upontheir centering pins c and d. These Shanks likewise -impart outthrust tothe inner walls of the bowl mouth 8.

The method of use, mode of operation and advantages of the improvedunderreamer constituting the invention will be understood from theforegoing description, taken in connection with the accompanyingdrawingl` and the following statement:

he parts of the underreamer are readily assembled together by applyingthe cutters to the. pivot pins c and d and then introducing the rod 10with its spring 11 through the bowl mouth 8 'at the lower end of thebody and into the communicating bore 7 in the body. Thereupon the springis pushed up by inserting a suitable implement through the transverseslot 15, and the key is introduced through said slot and the slot 16,with the end thereofy having the opening 19 leading. The lug or head 16ais then brought into its final recess 17 and the cutter pin 18 is passedthrough the opening 19 in the key. The parts are now held assembledtogether subject to ready disassembling or dismantling or reversal ofthe steps thus described, for the purpose of removing the cutters fromthe springactuated rod to permit replacement, sharpening, dressing orrepair thereof, such sharpening or dressing being frequentlyl necessary,due to the heavy service to whic underreamer cutters are subjected. Whenremoving the key 14 a suitable implement is applied to the leading endthereof. yThe key is driven out in the direction opposite to that inwhich it is inserted. With the parts assembled, the cutters ma now bedrawn downwardly into the position shown in Fig. 2, the bearings' 20riding over the upper spreading bearings 9u and the shoulders 20g,riding down onto the lower spreading bearings 9". The stop pin e may nowbe introduced within the hole 13 and entered in the slot 16, holding thecutters down against the compression of the spring 11, whereupon thecutters may be introduced within the casing at its upper end, and theunderreainer then lowered on the` cable to that point at which thecutters escape beneath the shoe or lower end of the casing.' After thecutters have been so introduced in the casing, the stop pin e iswithdrawn from the hole 13, and the spring freed for action to cause thecutters toexpand when brought to the position last stated beneath thecasing, the shoulders 20*g riding upwardly over the lower spreadingbearings 9, the bearings 20 riding upwardly over the upper spreadingbearings 9, causing first an abrupt expanding action of the cuttersfollowed by a finally more modified expanding action, until the ridingshoulder 203 is brought into engagement with the upthrust shoulder 8a atthe lower end of the reamer body mouth. Inasmuch as each cutter ispivotally mounted in the main at that side of the longitudinal axis ofthe reamer body in w-hich its path of expansion lies, the expandingaction is all utilized for the out ward projection of the body 20c ofthe cutter, to produce a full and accentuated expansion, which coincideswith a minimum upward ride of the cutter over the spreading bearings.Extreme expansion of the cutters is thus provided, insuring a completereaming action, or the complete reaming away of the annular shoulder orobstruction beneath the casing. This is of high importance inunderreaming work, and the invention provides for obtaining such highlyimportant spread or expansion within the small range of play possible orfeasible to be accommodated in a tool of the relatively compact or smallform or dimensions permitted by the conditions under which its operationand use take place. Likewise, such extreme expansion is permitted inaccordance with the invention without diminishing the strength andstress resistance of the working parts, or inviting breakage or failurethereof.

When it is desired to withdraw the reamer from working position, afterreaming the desired extent of formation to per mit further lowering ofthe casing, the underreamer body A is drawn upwardly by thestring-carrying cable carrying with it the cutters until the ridingbearings 20@ engage with the shoe or lower end of the casing, whereuponthe cutters are ternporarily held against vertical movement while thebody continues to rise, the relative movement so produced causing thebearings 20h to ride downwardly and inwardly upon the upper spreadingbearings 9, and subsequently the shoulders 20s to ride downwardly andinwardly upon the lower spreading bearings 9b. This downward and inwardcollapsing movement is initiated immediately, avoiding any pinch asbetween the cutters and the lugs, due to the slight downward inclinationof the upper spreading bearings 9, lVith the parts brought to thepositions shown in Fig. 2, upward urge being given the underreamerthrough the cable, the cutters and the correspondingly loweredspring-actuated rod will follow the body upwardly permitting the reamerto be withdrawn from the upper end of the casing.

One further particular advantage attaching to the pivotal suspension ofthe cutters at opposite sides of the longitudinal axis of theunderreamer, consists in the resultant disposition of the cutters eachapproximately in a vertical plane when in collapsed position. Owing tosuch disposition the cut to the longitudinal axis of the reamer, re-

sults in unobstructed lowering of the reamer through the casing. Onegreat difficulty attending the use of underreamers has always been thistendency of the cutters to stick and jam in the casing. This tendencyhas at times rendered it necessary to tie the cutters together beforeintroducing them `through the casing. No such tying or otherprecautionary measure is necessary with the reamer of the presentinvention.

t is manifest that many variations, changes and modifications, all withrelation to the foregoing description and statement and the showing ofthe drawing, may be made, in practicing the invention and adapting it tovarying conditions of use and service, without departing fromthe spiritof the invention and a fair interpretation thereof.

Having thus disclosed our invention, we claim and desire to secure byLetters Patent l. In an underreamer, a. body and a pair of cutters, thebody and cutters having interengaging means for causing expansion of thecutters,cutter supporting and actuating means including a springactuated plunger having a lower centrally aligned Hat head with oppositeparallel faces, the cutters having each a flat laterally offset shank,which shanks fit flatly one against one face and the other against theopposite parallel face of the fiat head, and pivoted connections for thecutters to the head embodying two pivots, one for one cutter at one faceof the head and the other for the other cutter at the opposite face ofthe head, said pivots being parallel to each other and at right anglesto the head faces and spaced apart on lopposite sides of a centrallongitudinal plane perpendicular to the head faces.

Q. In an underreamer. a body and a pair of cutters, the body and cuttershaving interengaging means for causing expansion of the cutters, thecutters being swingingly movable in a plane of movement longitudinal andcentral of the body, said cutters ha v ing flat shanks which overlapeach other and lie at opposite sides of the central longitudinal planeof movement of the cutters. and cutter supporting and actuating meanswhich include two-pivots upon one of which one cut- In testimony'whereof We have signed our ter shank is mounted and on the other 0fnames to this specification in the presence 0f 10 which the other cuttershank is mounted, said two subscribin Witnesses.

- pivots being'parallel to each other and par- E IHU' C. WILSON.

allel to and spaced apart on opposite sides WILLIAM `W. WILSON. of, acentral longitudinal plane which is Witnesses: perpendicular to thelongitudinal plane of ALFRED I-I. DAEHLER,

movement of the cutters. C. A. NIMMO.

